More than 1,000 professionals specializing in scientific and technical work landed jobs last month as Colorado’s unemployment rate dipped one-tenth of a percentage point to 3.5 percent, labor officials said Friday.

The rate was nearly a percentage point lower than the 4.4 percent recorded in April 2006 and was the lowest since June 2001, the Colorado Department of Labor and Employment said. The national rate essentially remained stable at 4.5 percent last month.

“While conditions in Colorado’s job market are favorable this spring, rising gas prices, a tepid national economy and softness within some segments of construction continue to constrain overall employment growth,” Donald Mares, the department’s executive director, said in a statement.

Sixty of the 64 counties also recorded lower unemployment rates, which range from 2 percent in Yuma County to 7 percent in Costilla County.

About 3,600 jobs were created across all industries last month to put the nonfarm work force at 2.32 million, according to the department’s seasonally adjusted figures.

Gains were led by the professional and business service sector, with 2,300 jobs; government, 1,900, primarily in local government offices; and education and health services with 700, the seasonally adjusted figures showed.

Seven industry sectors had losses, led by manufacturing with 1,100; construction, 700; and other services, 300.

Florida’s state social services agency investigated Nikolas Cruz’s home life more than a year before police say he killed 17 people at his former high school, closing the inquiry after determining that his “final level of risk is low,” despite learning that the teenager had behavioral struggles and was planning to buy a gun, according to an investigative report.